The Cleveland Family Study (CFS) is the largest family-based study of sleep apnea worldwide, consisting of 2,284 individuals (46% African American) from 361 families studied on up to 4 occasions over a period of 16 years. The study was begun in 1990 with the initial aims of quantifying the familial aggregation of sleep apnea. NIH renewals provided expansion of the original cohort (including increased minority recruitment) and longitudinal follow-up, with the last exam occurring in February 2006.
The CHAT is a multi-center, single-blind, randomized, controlled trial designed to test whether after a 7-month observation period, children, ages 5 to 9.9 years, with mild to moderate obstructive sleep apnea randomized to early adenotonsillectomy (eAT) will show greater levels of neurocognitive functioning, specifically in the attention-executive functioning domain, than children randomized to watchful waiting plus supportive care (WWSC). Other outcomes assessed included other indices of neurocognitive functioning (learning and memory, information processing, etc.), physical growth, blood pressure, metabolic profile, symptoms and quality of life. Physiological measures of sleep were assessed at baseline and at 7-months with standardized full polysomnography with central scoring at the Brigham and Women’s Sleep Reading Center. In total, 1,447 children had screening polysomnographs and 464 were randomized to treatment.